Starting switch for motors



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s R O w O .SM% NM1 OF. sunl RC1 www WM Mmm *.I LMF A T s Aprll 13 1926Patented Apr. 13, 1926.

UNITED STATES 1,580,161 PATENTN OFFICE.

LAWRENCE PERSONS, OF CHICAGO, ILLINOIS, ASSIGNOR TO COOK ELECTRIC COM-PANY, 0F CHICAGO, ILLINOIS, A CORPORATION 0F ILLINOIS.

STARTING SWITCH FOR MOTORS.

Application filed May 11, 1923.

To all whom t may concern.'

Be it known that I, LAWRENCE M. PER- soNs, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements in StartlngSwitches for Motors, of which the following is a specification.

In motors, especially of the alternating current type, it is usual toprovide a starting circuit which is broken after the motor has attainedits normal speed. The present invention relates to a starting switch ofthis type which shall be economical to manufacture, ellicientinoperation, and which shall be of long duration.

The invention is exemplified in the combination and arrangement of partsshown in the accompanying drawing and described in the followingspecification, and it is more particularly pointed out in the appendedclaims.

In the drawing- Fig. 1 is a sectional View of a motor showing parts ofthe starting switch in elevation;

Fig. 2 is a View similar to Fig. 1, having the starting switch parts insection; and

Fig. 8 is a section on line 3-3 ofFig. 2.

In the drawing, the numeral 10 designates a motor shaft journaled inbearings 11 on a casing 12. Secured to the shaft 10 is an armature 13having a cover plate 14 at the end thereof. Field poles 15 are supportedby the casing 12 about the armature 13 in the usual manner. A collar 16is interposed between the end of the armature 13 and the frame 12 tohold the parts in proper spacedrelation. Slidably mounted on the collar16 is a sleeve 17 having arms 18 extending radially therefrom atopposite sides thereof.

A pair of arcuate members 19 are provided with hooks 20 which engageopenlngs 21 in the end plate for the armature 13. These arcuate members19 are provided with coil springs 22, one at each side of the sleeve 17,which tend to draw the members 19 inwardly. The members 19 areperforated at 23 to receive the arms 18 so that the inward movement ofthe members 19 slides the 4 sleeve 17 to the right, as viewed in Figs. 1

and 2.

The sleeve 17 is provided with a ring 24 secured to the end thereof inposition to engage a conductor ring 25. The ring 24 Serial No. 638,207.

is made of hard fiber or other suitable insulating material. The ring 25is supported by a series of hooks 26 disposed in circular arrangementabout the ring 25 and mounted on an insulation plate 29 secured to thecasing 12. The ring 25 is free to rotate, in the confines of thesupporting hooks 26 and is resiliently pressed to the left, as viewed inFig.v2, by springs 27 attached to the insulation block 29.

,A pair of-.contact members 28 are mounted on the insulating block 29 onthe casing 12 and are in position to engage the contact ring 25 when thering is pushed to the right by the insulator ring 24, as shown inFig. 1. The contacts 28 have conductors 30 attached thereto so that whenthe contacts are con'- nected by the ring 25 the circuit is com'-ypleted through the starting coils of the motor.

l/Vhen the armature is at rest the parts are held in the position shownin Fig'. .l by the springs 22 so that the starting circuit is closed.When the armature attains full speed the arcuate members 19 are swungoutwardly by centrifugal force to the position shown in Fig. 2, thusretracting the sleeve 17 and withdrawing the ring 24 from contact withthe conductor ring 25. This permits the'springs- 27 4to force theconductor ring 25 away from the contacts 28 and break the startingcircuit afterTthe motor has attained full speed.

At the time the motor starts to rotate the frictional contact of thering 25 upon the springs 27 and contact members 28 will hold the ring 25from rotation and' the ring 24 will slide upon the ring 25.` When thecurrent isshut off and the motor begins to decrease in speed the ring 24will engage the ring 25 and since at the time of engagement the ring 25is free from contact with the terminals 28, it will begin to rotate thearmature and will attain suflicient momentum so that when it is broughtinto .engagement with the contact pieces 28 it will'continue to Amovefor a sufficient distance to provide a wiping engagement with thecontact members, thus keeping the contact surfaces bright. It will benoted, however, that this wiping engagement occurs at the time that thecurrent is shut off, but when current is flowing there is no movementbetween the contacting parts. The amount of relative movement is reducedto the'minimum necessary to keep the parts bright and never takes placewhen current is flowing so that the wear between the contacting parts ofthe make and break switch is reduced to a minimum, thus greatlyincreasing the life of the switch.

I claim:

1. A starting switch for a motor having a rotor, said switch comprisinga contact member Supported independently of the rotor and rotatableabout the axis thereof, spaced stationary terminals, and means on saidrotor for actuating said contact member to connect said terminals andclose said switch.

2. A starting switch for a motor having a rotor, said switch comprisinga contact ring, and an insulated member on said rotor arranged to engagesaid contact ring to close said switch and to impart temporary rotarymovement by frictional force to said ring at the time the switch isclosed.

3. A starting switch vtor an electric motor having a stationary frameand a rotor therein, said switch comprising a pair of contact membersstationarily mounted onl said frame, a contact ring rotatably mounted onsaid frame, and an' insulated member mounted on said rotor for engagingsaid ring to close said switch.

4. A starting switch for an electric motor having a stationary frame anda rotor therein, said switch comprising, a pair of contact membersmounted on said frame, a contact ring mounted on said frame to rotateabout an axis concentric with the axis of said motor and to moveparallel with said axis, and a centrifugal governor member on said rotor:tor engaging said ring to close said switch when said rotor reaches aprev determined speed.

5. A starting switch for an electric motor havingl a stationary frameand a rotor therein, said switch comprising a stationary contact membermounted on said frame, a conductor movably supported adjacent saidcontact member, `and an insulated member mounted on said rotor forengaging said conductor to close said switch when said rotor attains apredetermined speed, said conductor being movable by contact with saidvinsulated member in the direction of rotation of said rotor.

6. In a. starting switch for an electric motor having a stationary frameand a v`substantially diametrically member into engagement with saidterminal member, said means being adapted to 1mpart a wiping movement tosaid contact pember when it engages said terminal memer. v

7. In a starting switch for an electric motor having a stationary frameand a rotor thereon, the combination with a terminal member for thestarting circuit ot Said motor, of a contact member rotatable about theaxisof said rotor for engaging said ter` minal member to close saidswitch, centrifugally actuated means for holding said switch' closed butpermitting rotation of said rotor while said Contact member remainsstation# ary, said actuating means being arranged to impart movement tosaid Contact mem.

ber while closing said switch to `give a ,wip-

ing engagement between said contact meme' ber and terminal member.

8. In ,a starting switch for an electric motor having a rotor the.combination with a pair of terminal and a stationary frame,4

members mounted on said frame at points opposite one another, a contactring for ngaging said terminal members being mounted on said frame forrotation about the axis of said rotor and movable in the direction ofsaid axis into and out of engagement with said terminal members, springsfor holding said ring away from said terminal members, a lring of in-Sulating'material carried by said rotor and movable into and out ofsliding contact with said contact ring, centrifugal means for actuatingsaid insulator ring to Vforce said contact ring into engagement withsaid terminal members and to impart slight rotation to said ringrelativeto said terminal members at the time the switch is closed by said ring.

In testimony whereof I have signed my name to this specification on this15th day

